Matrix device.



F. J. BONNALIE.

MATRIX DEVICE.

APPLICATION 111513.010. 22, 1914.

Patented Dec. 21, 1915.

cowMnm PLANOURAPH con WASHINGTON. D c.

V Z 'oaZZ whom z'fimay concern-.5 I Y {PATENT e es FRED RICK onn-iacivNAnIE,"orfonnsrnn, ENGLAND.

MATRIX nnvron" Be it known that L'Fnnnnnrox JOHN NALIE, a subject of the .King of Great Britain, and resident of? Abbey Square, .Chestenin the county ofGhest'er', England, have invented new and useful Improve ments in Matrix Devices, of which the follOWlIlgdS'itSlQQClfiCatlOIl. I .;.Th1s inventlon relates to. matrix devices for use in, stopping orfilling teeth or for similar purposes and comprises improvements n the invention formmgthe sub ect of my prior-Patent No. 1,097 ,520, dated May 19th, 1914;

said patent, the ends of the looped matrix band after being passedl closely together through a slot ina frame or holder-and in engagement with aroller, are secured by means of a set-screw within a slot in a block mounted upon a rodv which s adapted to and if it be desired to release the b and from the holder when the device is in the mouth of a patient, as is found to be an advantage in practice, it is necessary to pass a suitable tool into the mouth'in order to loosen the set-screw. The latter is-also liable to come"- into contact with the rubber and clamp gum during a usually placed around the stopping or filling operatiom Now the present. invention to provide an improved construction OL- matrixdevice in which the setscrew isso arranged that it .can be'readily loosened from outside of the mouth of the patient and at the same time will notinterf'ere with the aforesaid rubber and clamp.

According to this invention the rod to which the block is fixed, is made hollow for the reception of the set-screw which extends rearwardly of the matrix device beyond the rear end of the said hollow rod so that when the device is in use, the head of the screw is outside of the mouth'and the screw can thus be easily turnedby hand. It is alsoimpossible by this arrangement for the set-screw to come into contact with the rubber or the clamp because it extends r'earwardly and not forwardly from the slot in the block in which the ends of the matrix band are clamped. The set-screw may be threaded In thev first construction v of matrix device. 7 described in the specification of the afore;

has for object v Specification of Letters Patent. Patentd Dec. 21, {$515. 1 Application filed December 22, 1914. Serial No. 878,551.

trated in the drawing, the frame or holder carrying the matrix band a consists as in the previous inventionof an L-shaped member I) one arm of which is provided with a transverse slotfZ having a roller 0 mounted therein for facilitating the movement of the band a through the slot and the other arm of which carries a tubular stem 0 within which a rod (6 is adapted to move axially. In the present invention, however, this rod d is made hollow for the reception of the rearwardly extending set-screw n, and also the block 6 is provided withan axial hole 6 which forms a continuation of the bore of thehollow rod (Z as will be clearly seen from Fig. 3, and extends as far as'the slot m in tli eiblock 6, wherein the ends of the matrix band a are adapted to be clamped; so that the forward end of. the set-screw n may enter the slot and clamp the ends of the band. vTheset-screw n is suitably screwthreaded for part of its length at or near its I forward end, as indicated atun in Fig. 3,

forv engaging with a female-threaded portion on the interior of the hollow rod d or in the hole 6 or both within the hollow rod dand'the hole 6. The rear end of the setscrew it projects beyondthe rear end of the hollow rod (Z and is provided with a milled head as shown so that it can be turned when desired.

It will now be readily understood that the setrscrew n can be easily turned by hand from outside the patients mouth when the matrix device is in use, consequently without necessitating'the use of a tool for the purpose, and therefore the matrix band a can be readily released from the holder when the device is in the mouth of a patient thereby also avoiding any possibility of injuring the stopping or filling.

The hollow rod d is screw-threaded externally at or toward its rear end as at h for the reception of a nut is for moving the rod boss l-onthe nut, see especially Fig. 2. The I nut is thus prevented from moving axially but whichever wav it be turned 1t Wlll causemovement of the hollow rod (Z.

Moreover, in order to indicate when the slot m in the block 6 and the slot Z in the L- shaped part b of the holder are disposed opposite each other so as to enable the ends of the band a to be readily passed through the slots prior to the clamping with the set screw n, the block and the slotted arm of the member I) may be provided with indicating marks, as shown for instance at 5 in Fig.

1, these marks being in alinement when the two slots aforesaid are opposite each other.

I claim 1. A matrix device for use in filling teeth I and for similar purposes, comprising a flex ible matrix band bent into the form of a loop,ea frame having a slot through which both ends of said band are passed closely together, a hollow rod axially movable upon said frame, a clamp member at the forward end of said hollow rod, a set-screw adapted to impinge on said band for clamping the ends of the latter to said clamp member, said set-screw extending rearwardly from the clamp member through said hollow rod and having its head beyondthe rear end of the rod, and adjusting mechanism for effect-j ingaxial movement of said rod.

2. A matrix device for use in filling teeth and for similar purposes, comprising a flexible matrix band bent into the form of a loop, a tubular frame having a slot at one end through which both ends ofsaidband are passed closely together, a roller mounted in said slot and engaged by said band, a hollow rod axially movable upon said frame, a clamp member at the forward end of said hollow rod, a set-screw adapted to impinge on said band for clamping the ends of the latter to said clamp member, said set-screw extendingrearwardly from the clamp member through said hollow rod and having its head beyond the rear end of the rod, and adjusting mechanism for effecting axial v movement of said rod.

3. A matrix device for'u'se in filling teeth and for similar purposes, comprlsing a-fiexible matrix band bent into the form of a loop, a tubular frame having aslot through which both ends of said band are passed I closely together a roller mounted in said slot and engaged by said band, a hollow rod axially movable upon said frame, a block on the'forw'ard end of said hollow rodpro videdwith aslot for receiving theends of Z said band, and with a screw-threaded hole extending from the slot to the rear ofthe block, a set-screw for "clamping said ends in said slot, said set-screw engaging at its front end in said screw-threaded hole and;

extending rearwardly through the borerof said hollow rod'so that'itsheadis beyond the rear end of the rod, and adjus'tingmechanism for effecting axial movement of said hollow rod.

4. A matrix device for use in filling teeth and for similar purposes, comprising a flexible matrix band bent into the form ofa loop, a member having a slot through which both ends of said band arepassed closely together,-a roller mounted in said slot and engaged by said band, a tubular stem at tached to said slotted member a hollow rod in said tubular stem, a clamp member at the forward end ofsaid hollow rod, a set-screw for clamping the ends of said band to said clamp member, said set-screw extending rearwardly from the clamp member through said hollow rod and having its head beyond the rear end of the rod, a nut threaded on the rear end of the rod, a grooved boss on said nut, anda bracket at the rear end of said tubular stem provided with a projecting part for engaging the grooved boss of the nut, set'fort j V r FREDERICK JOHN BONNALIE. Witnesses:

WV. G. HILL,

R. JAMES.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, V j Washington, D. C.

substantially as and for the purpose 

